Welker got a second opinion on his injured right elbow from Dr. James Andrews, who recommended and performed the surgery in Gulf Breeze, Fla. Welker, 28, was 1-1 with a 4.91 ERA, 15 strikeouts and 11 walks in nine appearances for Triple-A Indianapolis this season. He last pitched on May 3 before being sidelined with the elbow ailment.

Welker has a fastball that can touch the upper 90s and spent parts of the last three seasons in Triple-A. He also had a brief stint in the Majors last season, and in two appearances with the Pirates last June, Welker pitched 1 1/3 scoreless innings.

Stephen Pianovich is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.